Electrical apparatus for heating liquids.



W. H. SIVHTH. ELECTRICALAPPARATUS FOR HEATING LIQUIDS. APPLICATION FILED mac-12, 1916.

1 278,775 Patented Sept. 10, 1918.

UNITED STATES PATENT OFFICE.-

WILLIAM HOGG SMITH, OF FALKIRK, ENGLAND, ASSIGNOR TO THE FILIBAR ELECTRIC HEATER, LIMITED, OF LONDON, ENGLAND.

Specification of Letters Patent.

Patented Sept. 10, 1918.

Application filed December 12, 1916. Serial No. 136,555.

To all whom it may concern.

Be it known that I, WILLIAM Hose SMITH, of #57 Orchard street, Falkirk, Stirlingshire, England, have invented a new and useful Improvement in Electrical Apparatus for Heating Liquids, and do hereby declare the nature of this invention and in what manner the same is to be performed to be particularly described and ascertained in and by the following statement.

This invention relates to-electrical apparatus for heating liquids of the type including a tube adapted to be traversed by the liquid to be heated and packed with granules which constitute a resistance in an electrical circuit, such tube being closed at the ends by plugs constituting terminals.

I am aware that it has been proposed to provide a variable resistance with resilient means tending to force the terminals into effective electrical contact with the adjacent carbon elements and to compress said elements so as to vary the resistance. I wish it to be understood, however, that the present invention is exclusively concerned with the art of heating liquids and that the claim is to be construed accordingly.

Electrical liquid heating apparatus of the type referred to is open to the objection that the granules contacting with the plugs become disintegrated and the particles are liable to be washed out of the apparatus so that effective contact between the plugs and the granules is eventually disestablished.

This objection is overcome, according to the present invention, by the provision of means whereby the surfaces of the plugs are maintained at a distance apart equivalent to the height of the column of granules.

To this end, the present invention consists in the provision at one end or at each end of the tube of an axially extensible plug consisting of two parts, one of which is movable axially, cooperating with resilient means tending to force the contact face into efi'ec- Copies of this patent may be obtained for five cents each, by addressing the Commissioner tive electrical contact with granules.

As preferably constructed, the plug is composed of a rod and a tubular contact piece capable of telescoping relatively there to and a spring which is housed in the tubular member and acts to force the contact piece into efiective electrical contact with the granules.

The invention is illustrated in section in the figure of the accompanying drawing.

As shown, the improved apparatus comprises a tube 1 containing granules c. 9., carbon granules.

Fitted in each end of the tube is a plug 2 one or each of which comprises a relatively immovable rod 3 in relation to which is adapted to telescope a tubular contact piece 4 presenting a face for contact with the adjacent granules.

Interposed between the rod 3 and the piece a is a spring 5 c. 9., a helical spring, which acts to force the contact piece into effective electrical contact with the adjacent granules.

Ingress of cold liquid to, and egress of heated liquid from, the tube is permitted through lateral inlet and outlet connections (not shown) located adjacent to the upper plug and lower plug respectively.

Having now particularly described and as certained the nature of my said invention and in what manner the same is to be performed I declare that what I claim is A terminal for water heaters comprising a granule-containing tube, a cup in the end of the tube having its convex portion hearing against the granules and its concave portion facing the open end of the tube, a stationary plunger extending into the cup and a spring in the cup and bearing against the plunger.

The foregoing specification signed at Glasgow this eighth day of January, 1917.

WILLIAM JIOGG SMITH.

the adjacent of Patents,

Washington, D. 0. 

